1. Field of the Invention
The present invention generally relates to a wheel suspension for a vehicle; and more specifically to a motor vehicle having a transverse leaf spring arranged transversely relative to a vehicle longitudinal axis.
2. Description of Related Art
Transverse leaf springs may be used in vehicle wheel suspensions as an efficient solution for weight reduction as they replace the superstructure springs and the stabilizer. In order to function as the superstructure springs and the stabilizer the leaf springs must be able to ensure, at the same time, a degree of rolling stability (resistance against mutually opposing vertical movement of the wheels) and a degree of lifting stability (resistance against vertical movement of the wheels in the same direction). Typically, these levels of rigidity are different. The transverse leaf spring, with a resiliently loaded mass, such as for example the vehicle superstructure or an auxiliary frame which is connected to the vehicle superstructure, must be secured at two different inner articulation locations with a specific lateral spacing with respect to each other. The outer ends or outer articulation locations of the transverse leaf springs are connected to the non-resiliently loaded mass of the vehicle, for example, the wheels, wheel carriers, brakes, components of the wheel suspension, etc. In this manner, a four-point bending system is defined.
The structure of the inner articulation locations is generally rather complex since they must comply at the same time with various requirements. For instance, a high level of vertical rigidity is desirable since vertical resilience of the inner articulation locations influences the resulting rolling and lifting rigidity. In particular, a lower level of vertical rigidity leads to a lower relationship between rolling and lifting rigidity, which is, however, undesirable. A large relationship between rolling and lifting rigidity ensures that the wheel suspension provides a high level of resistance against rolling movements of the vehicle superstructure while, at the same time, providing adequate resilience in a vertical movement direction for good travel comfort.
A low lateral rigidity of the inner articulation locations is further desirable in order to enable a deformation of the central portion of the transverse leaf spring during the lifting and rolling movements of the vehicle. Such deformations of the transverse leaf spring require that the lateral spacing between the inner articulation locations be able to change. Furthermore, a low torsion rigidity of the inner articulation locations is also desirable in order on one hand to enable the deformations in the central portion thereof and on the other hand to prevent the bearing rigidity of the inner articulation locations making a significant contribution to the overall rolling and lifting rigidity of the transverse leaf spring-parasitic contribution.